1. Field of the Invention
The present invention relates to a motion transmission module, and more particularly to a motion transmission module with a cooling device.
2. Description of the Prior Art
When a motion transmission module (such as ball or roller screw) is used in heaving load conditions, with the increase in axial load, the temperature of the nut will also increase, which will affect the running accuracy. Hence, the existing nuts are normally provided with a cooling system.
Referring to FIG. 1, a conventional technique for cooling the nut of a ball screw is shown, wherein the nut 11 is formed with a plurality of straight holes 111 and arc-shaped grooves 112, and at the front end and flange end of the nut 11 are disposed anti-leak cushions 113 and an end cap 114, so as to form a cooling system.
Since it has to arrange the end cap 114 at the end surface of this cooling nut, the length of the nut 11 must be increased (as compared to the nut without cooling system), which will result in the reduction of the travel length of the ball screw or roller screw equipped with such cooling nut.
As shown in FIG. 2, another conventional nut cooling structure is shown, wherein the nut 12 is formed with an inlet 121 and an outlet 122 for inputting and discharging of cooling liquid, and an outer cover 13 is mounted on the nut 12 to form a cooling groove 14, and then two O-rings 15, 16 are used to prevent the cooling liquid leakage.
The outer cover 13 increases the outer diameter of the nut 12 as compared to the nut without cooling system, so that it is inconvenient to the user who uses the ball or roller screw which was originally equipped with a non-cooling-system nut, since it has to redesign the nut mounting seat when the non-cooling-system nut is replaced with a cooling nut of the same size.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.